1. Field of the Invention
The present invention relates to an image reading/recording apparatus having an image reading unit for reading image information, and an image forming unit for forming an image and recording it on a recording medium.
2. Related Background Art
As a conventional image reading/recording apparatus, a facsimile apparatus, which has an image reading unit and image forming unit, and has a function of communicating image information, is known. Facsimile apparatuses used in offices and the like, and especially, compact, desktop apparatuses, must meet requirements for further size and cost reductions, and higher-speed processing.
The arrangement of a conventional facsimile apparatus and the layout of circuit boards will be described below with reference to the sectional view in FIG. 4 and the perspective view in FIG. 5.
In the arrangement of the facsimile apparatus shown in FIG. 4, an image reading unit A is placed in the upper front portion (upper left portion in FIG. 4) of an apparatus body (to be simply referred to as a body hereinafter), and an image forming unit B is placed behind the unit A. Image information of an original read by the image reading unit A is transmitted to another facsimile apparatus in the facsimile mode, or is transferred to and recorded by its own image forming unit B in the copy mode.
The image reading unit A conveys an original 113, and reads image information described on the original 113. Originals 113 stacked on an original table 114a and auxiliary table 114b are picked up one by one by a pickup roller 114c and pickup piece 114d, which is pressed against the roller 114c, and the picked-up original 113 is conveyed by a pair of convey rollers 114e. A pressing means 114f presses that original 113 against a contact sensor 115 of an image reading means to read image information on the original 113. After that, the original 113 is exhausted onto a tray 106b outside the apparatus by a pair of exhaust rollers 114g. 
The image forming unit B irradiates a photosensitive drum 107 as a rotating image carrier with an optical image based on image information received from another facsimile apparatus or that read by its own image reading unit A via an optical system 101, and forms an electrostatic latent image corresponding to the image information by selectively exposing the surface of the photosensitive drum 107. A developing unit prepared as a process cartridge C then forms a toner image on the surface of the photosensitive drum 107.
On the other hand, a convey means 103 picks up and conveys the uppermost one of recording sheets 102 horizontally stacked in a paper cassette 103a, which can be pulled out from one end of a paper feed unit D. The conveyed recording sheet is reversed via a U-turn path, and is then conveyed to a transfer means 104. The transfer means 104 applies a voltage of a polarity opposite to that of a toner image formed on the photosensitive drum 107, thereby transferring the toner image on the photosensitive drum 107 onto the recording sheet 102. After that, the recording sheet 102 is conveyed to a fixing means 105, and the toner image on the recording sheet 102 is fixed thereon upon application of heat and pressure. The fixed recording sheet 102 is exhausted onto a face-down tray 106a in the face-down exhaust mode which exhausts the recording sheet 102 with the recorded surface facing down or onto the face-up tray 106b in the face-up exhaust mode which exhausts the recording sheet 102 with the recorded surface facing up.
The layout of the circuit boards will be explained below. A power supply board 120 having a power supply input unit 120a, high-voltage circuit, and the like, and a control board 122 having a CPU, body control circuit, image processing circuit, and the like are juxtaposed at the right and left positions below the image forming unit B and above the surface of the paper cassette 103a, as shown in FIG. 5. The power supply input unit 120a is exposed outside the body from a hole open to a right side surface 133 of the body and receives electric power via a power supply cord (not shown). An NCU board 123 having a communication circuit is placed above the control board 122 on a left side surface 134 of the body on the left side of the image forming unit B. Furthermore, a modular board 124 having a modular jack connector for connecting the apparatus to a telephone line is placed below the NCU board 123 and control board 122. The modular jack connector (not shown) is exposed outside the body via a hole (not shown) open to the left side surface 134 of the body, and is connected to a line via a communication cable (not shown), thus allowing communications of image data and the like.
The power supply board 120 and control board 122, the power supply board 120 and NCU board 123, the control board 122 and NCU board 123, and the NCU board 123 and modular board 124 are respectively connected to each other via cables, connectors, and the like to supply electric power, exchange signals, and connect ground.
In this fashion, in the arrangement for conveying the recording sheet 102 from the paper cassette 103a to the transfer means 104 while being reversed via the U-turn path, the respective circuit boards are efficiently laid out to avoid the convey path of the recording sheet.
However, in the above prior art, a power supply cable for electrically connecting the power supply board 120 and NCU board 123 crosses the control board 122, resulting in complicated connections of cables. Also, an insulating member is required between the cable and control board 122 due to limitations on safety standards, resulting in high parts cost, poor assembly, and high assembly cost.
The power supply cord is attached from the right side surface 133 of the body, and the communication cable for line connections is attached from the left side surface 134 of the body. Hence, when the user uses the apparatus on the desktop, these cords extend on the desktop and require extra spaces, thus broadening the installation space of the apparatus in practice.
Furthermore, since the recording sheet 102 is stored in the paper cassette 103a and is conveyed from the cassette 103a to the transfer means 104 while being reversed via the U-turn path, the size of the apparatus is determined by that of the recording sheet 102 that the apparatus can process, thus disturbing a size reduction. At the same time, the length of a recording sheet convey path from the leading end position of the recording sheet 102 to the transfer means 104 is prolonged, thus requiring a long convey time and disturbing high-speed image recording.
It is an object of the present invention to solve the aforementioned problems, and to provide an image reading/recording apparatus which simplifies the connection routes among boards to facilitate connections among the boards.
It is another object of the present invention to prevent a connection means for connecting boards from crossing other boards by placing the respective circuit boards along the neighboring ones of the bottom, side, and back inner surfaces of a body.
Other objects of the present invention will become apparent from the following detailed description of the embodiments to be described below.